1-(Arylsulfonyl)-2,3-dihydro-1H-quinolin-4-one derivatives as 5-HT(6) serotonin receptor ligands.

Piperazinyl derivatives of 1-(arylsulfonyl)-2,3-dihydro-1H-quinolin-4-ones have been identified with high binding affinities for 5-HT(6) receptor. In particular, 2-methyl-5-(N-methyl-piperazin-1-yl)-1-(naphthalene-2-sulfonyl)-2,3-dihydro-1H-quinolin-4-one (8g) exhibits high binding affinity toward 5-HT(6) (IC(50)=8nM) receptor with good selectivity over other serotonin and dopamine receptors.

Synthesis and SAR of (piperazin-1-yl-phenyl)-arylsulfonamides: a novel series of atypical antipsychotic agents.

(Piperazin-1-yl-phenyl)-arylsulfonamides were synthesized and identified to show high affinities for both 5-HT(2C) and 5-HT(6) receptors. Among them, naphthalene-2-sulfonic acid isopropyl-[3-(4-methyl-piperazin-1-yl)-phenyl]-amide (6b) exhibits the highest affinity towards both 5-HT(2C) (IC(50)=4 nM) and 5-HT(6) receptors (IC(50)=3 nM) with good selectivity over other serotonin (5-HT(1A), 5-HT(2A), and 5-HT(7)) and dopamine (D(2)-D(4)) receptor subtypes. In 5-HT(2C) and 5-HT(6) receptor functional assays, this compound showed considerable antagonistic activity for both receptors.

Discovery of 3-aryl-3-methyl-1H-quinoline-2,4-diones as a new class of selective 5-HT6 receptor antagonists.

A 5,7-dichloro-3-phenyl-3-methyl-quinoline-2,4-dione (11a) has been identified in a random screen as a lead for 5-HT(6) antagonist. During the lead optimization process, several analogs were synthesized and their biological activities were investigated. Within this series, several compounds display high binding affinity and selectivity for the 5-HT(6) receptor. In particular, 3-(4-hydroxyphenyl)-3-methyl-quinoline-2,4-dione (12f) exhibits high affinity (K(i)=12.3 nM) for 5-HT(6) receptor with good selectivity over other serotonin and dopamine (D(1)-D(4)) receptor subtypes. In a functional adenylyl cyclase stimulation assay, this compound exhibited considerable antagonistic activity (IC(50)=0.61 microM).

Synthesis and structure-activity relationship of 1H-indole-3-carboxylic acid pyridine-3-ylamides: a novel series of 5-HT2C receptor antagonists.

A novel series of 1H-indole-3-carboxylic acid pyridine-3-ylamides were synthesized and identified to show high affinity and selectivity for 5-HT(2C) receptor. Among them, 1H-indole-3-carboxylic acid[6-(2-chloro-pyridin-3-yloxy)-pyridin-3-yl]-amide (15k) exhibits the highest affinity (IC(50)=0.5 nM) with an excellent selectivity (>2000 times) over other serotonin (5-HT(1A), 5-HT(2A), and 5-HT(6)) and dopamine (D(2)-D(4)) receptors.

Individual and common inhibitors of coronavirus and picornavirus main proteases.

Picornaviruses (PV) and coronaviruses (CoV) are positive-stranded RNA viruses which infect millions of people worldwide each year, resulting in a wide range of clinical outcomes. As reported in this study, using high throughput screening against approximately 6800 small molecules, we have identified several novel inhibitors of SARS-CoV 3CL(pro) with IC(50) of low microM. Interestingly, one of them equally inhibited both 3C(pro) and 3CL(pro) from PV and CoV, respectively. Using computer modeling, the structural features of these compounds as individual and common protease inhibitors were elucidated to enhance our knowledge for developing anti-viral agents against PV and CoV.

Dendritic oligoguanidines as intracellular translocators.

A series of polyguanidylated dendritic structures that can be used as molecular translocators have been designed and synthesized based on nonpeptide units. The dendritic oligoguanidines conjugated with fluorescein or with a green fluorescent protein (GFP) mutant as cargos were isolated and characterized. Quantification and time-course analyses of the cellular uptake of the conjugates using HeLa S3 and human cervical carcinoma cells reveal that the polyguanidylated dendrimers have comparable translocation efficiency to the Tat(49-57) peptide. Furthermore, the deconvolution microscopy image analysis shows that they are located inside the cells. These results clearly show that nonlinear, branched dendritic oligoguanidines are capable of translocation through the cell membrane. This work also demonstrates the potential of these nonpeptidic dendritic oligoguanidines as carriers for intracellular delivery of small molecule drugs, bioactive peptides, and proteins.

Synthesis and evaluation of 4-hydroxyphenylacetic acid amides and 4-hydroxycinnamamides as antioxidants.

4-Hydroxyphenylacetic acid amides and 4-hydroxycinnamamides were synthesized and their antioxidant and neuroprotective activities were evaluated. Among the prepared compounds, 8b, and exhibited potent inhibition of lipid peroxidation in rat brain homogenates, and marked DPPH radical scavenging activities. Furthermore, and exhibited neuroprotective action against the oxidative damage induced by the exposure of primary cultured rat cortical cells to H(2)O(2), xanthine/xanthine oxidase, or Fe(2+)/ascorbic acid. Based on these results, we found that was the most potent antioxidant among the compounds tested.